Caffeine Intake Calculator
You're over the FDA's general 400mg/day guidance for healthy adults.
The FDA's 400mg/day is a population average — it's calibrated for roughly a 160lb (~72kg) adult, so it's too high for someone much lighter and unnecessarily conservative for someone much heavier. A more personalized rough guide many sources cite: about 6mg per kg of body weight, capped at 400mg. If you're pregnant, ACOG guidance caps intake at 200mg/day regardless of weight. This is general information, not medical advice.
Track today's caffeine from coffee, tea, energy drinks, and soda — checked against both the flat FDA limit and a more personalized, weight-based limit.
How it works
- Enter how many of each drink you've had today
- See your total caffeine in mg, compared to the FDA's flat 400mg/day guidance
- Optionally enter your body weight for a more personalized limit (~6mg per kg, capped at 400mg)
Frequently asked questions
Is 400mg of caffeine per day safe for everyone?
The FDA's 400mg figure is a population average, calibrated for roughly a 160lb (~72kg) adult. It's too high for someone who weighs much less, and unnecessarily conservative for someone who weighs much more — which is why this calculator also offers a weight-based estimate (~6mg per kg of body weight).
What about caffeine during pregnancy?
The American College of Obstetricians and Gynecologists (ACOG) recommends capping caffeine at 200mg/day during pregnancy, regardless of body weight. This calculator shows that as a separate note rather than baking it into the main limit.
Where do the mg-per-serving numbers come from?
Commonly-cited average values for standard serving sizes — actual caffeine content varies by brand and brewing method, so treat these as reasonable estimates, not exact figures for your specific drink.
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From the blog
Update history
- 2026-09-03 "Today's total" now changes color and size based on how close it is to your limit (green/normal → orange/larger → red/largest), so the comparison to the limit is visible at a glance, not just as two separate numbers.
- 2026-09-03 Each drink now has an original illustration icon, and quantities are sliders instead of number fields.
- 2026-09-02 Launched: caffeine intake calculator covering coffee, espresso, tea, energy drinks, and soda, with both the flat FDA limit and an optional weight-based limit. Entirely client-side.